The elucidation of the nature of ischemic brain edema is potentially of great value for the clinical management of stroke patients. The studies described above indicate that following ischemia there is a development of brain edema which is primarily of cytotoxic type. Only in later stages when there is damage to cerebral blood vessels and their increased permeability to BBB tracers, a leakage of serum components is adding a vasogenic component to overall picture of brain edema. These findings might be of importance for designing proper treatment of patients suffering from cerebral ischemia.